| 1 | /* |
| 2 | * XBM image format |
| 3 | * |
| 4 | * Copyright (c) 2012 Paul B Mahol |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include "libavutil/avstring.h" |
| 24 | |
| 25 | #include "avcodec.h" |
| 26 | #include "internal.h" |
| 27 | #include "mathops.h" |
| 28 | |
| 29 | static int convert(uint8_t x) |
| 30 | { |
| 31 | if (x >= 'a') |
| 32 | x -= 87; |
| 33 | else if (x >= 'A') |
| 34 | x -= 55; |
| 35 | else |
| 36 | x -= '0'; |
| 37 | return x; |
| 38 | } |
| 39 | |
| 40 | static int parse_str_int(const uint8_t *p, int len, const uint8_t *key) |
| 41 | { |
| 42 | const uint8_t *end = p + len; |
| 43 | |
| 44 | for(; p<end - strlen(key); p++) { |
| 45 | if (!memcmp(p, key, strlen(key))) |
| 46 | break; |
| 47 | } |
| 48 | p += strlen(key); |
| 49 | if (p >= end) |
| 50 | return INT_MIN; |
| 51 | |
| 52 | for(; p<end; p++) { |
| 53 | char *eptr; |
| 54 | int64_t ret = strtol(p, &eptr, 10); |
| 55 | if ((const uint8_t *)eptr != p) |
| 56 | return ret; |
| 57 | } |
| 58 | return INT_MIN; |
| 59 | } |
| 60 | |
| 61 | static int xbm_decode_frame(AVCodecContext *avctx, void *data, |
| 62 | int *got_frame, AVPacket *avpkt) |
| 63 | { |
| 64 | AVFrame *p = data; |
| 65 | int ret, linesize, i, j; |
| 66 | int width = 0; |
| 67 | int height = 0; |
| 68 | const uint8_t *end, *ptr = avpkt->data; |
| 69 | const uint8_t *next; |
| 70 | uint8_t *dst; |
| 71 | |
| 72 | avctx->pix_fmt = AV_PIX_FMT_MONOWHITE; |
| 73 | end = avpkt->data + avpkt->size; |
| 74 | |
| 75 | width = parse_str_int(avpkt->data, avpkt->size, "_width"); |
| 76 | height = parse_str_int(avpkt->data, avpkt->size, "_height"); |
| 77 | |
| 78 | if ((ret = ff_set_dimensions(avctx, width, height)) < 0) |
| 79 | return ret; |
| 80 | |
| 81 | if ((ret = ff_get_buffer(avctx, p, 0)) < 0) |
| 82 | return ret; |
| 83 | |
| 84 | // goto start of image data |
| 85 | next = memchr(ptr, '{', avpkt->size); |
| 86 | if (!next) |
| 87 | next = memchr(ptr, '(', avpkt->size); |
| 88 | if (!next) |
| 89 | return AVERROR_INVALIDDATA; |
| 90 | ptr = next + 1; |
| 91 | |
| 92 | linesize = (avctx->width + 7) / 8; |
| 93 | for (i = 0; i < avctx->height; i++) { |
| 94 | dst = p->data[0] + i * p->linesize[0]; |
| 95 | for (j = 0; j < linesize; j++) { |
| 96 | uint8_t val; |
| 97 | |
| 98 | while (ptr < end && *ptr != 'x' && *ptr != '$') |
| 99 | ptr++; |
| 100 | |
| 101 | ptr ++; |
| 102 | if (ptr < end && av_isxdigit(*ptr)) { |
| 103 | val = convert(*ptr++); |
| 104 | if (av_isxdigit(*ptr)) |
| 105 | val = (val << 4) + convert(*ptr++); |
| 106 | *dst++ = ff_reverse[val]; |
| 107 | if (av_isxdigit(*ptr) && j+1 < linesize) { |
| 108 | j++; |
| 109 | val = convert(*ptr++); |
| 110 | if (av_isxdigit(*ptr)) |
| 111 | val = (val << 4) + convert(*ptr++); |
| 112 | *dst++ = ff_reverse[val]; |
| 113 | } |
| 114 | } else { |
| 115 | av_log(avctx, AV_LOG_ERROR, |
| 116 | "Unexpected data at %.8s.\n", ptr); |
| 117 | return AVERROR_INVALIDDATA; |
| 118 | } |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | p->key_frame = 1; |
| 123 | p->pict_type = AV_PICTURE_TYPE_I; |
| 124 | |
| 125 | *got_frame = 1; |
| 126 | |
| 127 | return avpkt->size; |
| 128 | } |
| 129 | |
| 130 | AVCodec ff_xbm_decoder = { |
| 131 | .name = "xbm", |
| 132 | .long_name = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"), |
| 133 | .type = AVMEDIA_TYPE_VIDEO, |
| 134 | .id = AV_CODEC_ID_XBM, |
| 135 | .decode = xbm_decode_frame, |
| 136 | .capabilities = CODEC_CAP_DR1, |
| 137 | }; |